Toxic and Essential Trace Elements in Human Primary Teeth: A Baseline Study within the Mobatooth Biobank and the Norwegian Mother, Father and Child Cohort Study (Moba)

Abstract

The Norwegian Mother, Father and Child Cohort Study (MoBa) includes a nation-wide collection of deciduous teeth housed in the MoBaTooth biobank. The aim of the present study is to create a baseline for early-life metal exposure using dentine biomarkers. Deciduous teeth were collected in the MoBaTooth biobank, a sub-study of the MoBa-study. This study uses 94 primary teeth from children with no known medical conditions at the age of 6 months, a normal birth weight (2500-4500g) and an equal number of teeth shed between 2008-2013 and 2014-2019. A total of 48 girls and 46 boys are included to create a baseline to characterise retrospective exposure to toxicants during multiple early-life developmental periods. Estimates of weekly prenatal and postnatal exposure to 18 metals by measuring dentine concentrations have been made using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). Temporal trends in dentine levels differed from metal to metal. Girls had higher postnatal dentine Mn and Zn, compared to boys (p=0.020 for postnatal Mn-levels, and p=0.011 for postnatal Zn-levels). Deciduous teeth provide retrospective information on the intensity and timing of early-life metal exposure at weekly temporal resolution. Creating a baseline, future studies can use outcomes of conditions and illness in children in case-control-studies aiming at prevention. Using deciduous teeth, a novel noninvasive biomarker, characterising early-life exposure to 18 metals in approximately weekly increments during sensitive developmental periods extending from the second trimester to 4 months postnatally has been performed.

Note:
Funding declaration: The LA-ICP-MS analyses were supported by grants from Dentist Einar Bergersen’s legacy, The Research Council of Norway and the Institute of Clinical Dentistry, Faculty of Medicine at the University of Bergen. MA was supported by US National Institute of Health grants R35ES030435, U2CES030859, P30ES023515, R01ES026033, U2C ES026561.

Conflict of Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Ethical Approval: The establishment of MoBa and initial data collection was based on a licence from the Norwegian Data Protection Agency and approval from The Regional Committees for Medical and Health Research Ethics. The MoBa cohort is currently regulated by the Norwegian Health Registry Act. The approval number of the MoBaTooth Biobank from The Regional Committees for Medical and Health Research Ethics is 2007/5697-077.07. This study is also approved by The Regional Committee for Medical Research Ethics, with reference number 140805.

Keywords: Dentine biomarkerMetal mixturesPrenatal Exposure Early-life exposureChild healthTrace-elements